Press



g Au 10, 1937. J. ALBERTOLI 2,089,324

PRESS Filed Dec. 17, 1935 INVENTOR JOHN AL P TOL MM H15 ,ATTORNEY Patented Aug. 10, 1937 UNlTED STATES PATENT OFFICE 2 Claims.

My invention relates to improvements in presses, and particularly to a hydraulic pressure unit adapted for use in connection with hand operated presses, such for example as fruit presses, to supplement the pressures obtainable by the manual operation thereof.

It is among the objects of my invention to provide a hydraulic pressure unit which is simple, compact, rugged, and efficient; and which may be readily applied to a press and transferred from one press to another.

Another object is to provide a hydraulic pressure unit which will accommodate itself to inaccuracies of alignment, and irregularities in the surface to which pressure is to be applied.

Another object is to provide a hydraulic Pressure unit in which the liquid pressure medium is stored within a chamber in which the pressure applying piston operates, means being provided for efficiently transferring the liquid from one side of the piston to the other as desired.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following description of my invention. It is to be understood that Ido not limit myself to this disclosure of species of my invention, as I may adopt variant embodiments thereof within the scope of the claims.

Referring to the drawing:

Figure -1 is a side elevation of a press equipped with the hydraulic pressure unit of my invention, portions being broken away and shown in section todisclose the inner parts of the mechanism.

Figure 2 is a right side elevation of the hydraulic pressure unit as shown in Figure 1, the figure being drawn upon a reduced scale.

Figure 3 is a sectional plan View of the hydraulic pressure unit, the section being taken upon the line 33 of Figure 1.

In terms of broad inclusion, the hydraulic pressure unit of my invention comprises a pressure chamber mounted between a base plate and abutment which in turn are arranged to be placed over the feed screw and between the pressure plate and the feed nut of a press.

A piston is mounted within the chamber and 7 arranged to be displaced by liquid pumped into the chamber to cause a relative movement of the base plate and piston, the piston preferably being held against movement by the abutment. Preferably, the piston is connected to the abutment by a plurality of piston rods each of which is preferably loosely connected at opposite ends thereof to the piston and to the abutment so as to permit a limited shifting of the piston or the base plate, or both, relative to the abutment for accommodating inaccuracies of alignment and inequalities in the depth or on the surface of the material to be pressed.

The liquid for displacing the piston is preferably stored in the chamber upon the low pressure side of the piston, the liquid being pumped from the low pressure side to the high pressure side of the piston through a connection having its inlet so positioned that it will be closed by the piston for cutting off the supply of liquid when the piston reaches the limit of its normal movement in the pressure applying direction. A connection is provided to permit the return of the liquid to the low pressure side of the piston by pressure exerted by the piston itself. Appropriate valves are provided to prevent the flow of liquid in directions other than those desired for a particular phase of the pressing operation.

The hydraulic pressing mechanism is compactly arranged upon the base plate as a unit which may bereadily transported from place to place and transferred from one press toanother as desired.

In terms of greater detail, and referring particularly to the illustrative embodiment disclosed in the drawing, the hydraulic pressure unit of my invention comprises a base plate I having a central opening 2 through which the feed screw 3 of a press 4 may extend. The press 4 may be of the conventional fruit press type having a container portion formed of slats 6, and provided with a pressure plate 1' arranged to be forced downwardly upon material within the container by means of a feed nut 8 threaded upon the feed screw 3.

Upon the base plate I is mounted an inner cylinder 9 through which the feed screw 3 may extend, and an outer cylinder H concentric with the cylinder 9, the walls of the cylinders 9 and H being sufiiciently spaced to provide an annular chamber [2 therebetween. An annular piston I4 is mounted within the chamber [2, the piston being provided with a suitable pressure retaining cup washer [6.

The piston 14 is connected to an abutment ll above the chamber 12 by means of a plurality of piston rods 18 extending outwardly from the chamber through openings l9 formed in a cover plate 28- mounted on the tops of the cylinders 9 and I l-. The piston rods I8 are preferably loosely connected to the piston and to the abutment to permit a slight shifting of the rods, either transversely or pivotally, so as to allow for inaccuracy of alignment and to accommodate a slight tilting of the base plate I- and pressure plate 1.

For example, the lower ends of the rods I8 may seat within sockets 2I formed in lugs 22 upon the top of the piston, cotter pins 23 or other suitable securing means being applied through registered openings in the lugs 22 and the ends of the rods I8 to hold the rods in place in the sockets, and to permit a limited pivotal movement of the rods relative to the pistons Id.

The upper ends of the rods I8 are prefer-ably provided with shoulders 25 arranged to seat against the under side of the abutment IT, with reduced extensions 26 extending through openings 27 in the abutment I1. The openings 21 are of larger diameter than the extensions 26 so as to allow a limited amount of transverse or tilt.- ing movement of the extensions within the openings. A retaining member, as for example a cotter pin 28, is provided in the end of each extension 26 to hold the rods I8 in engagement with the abutment I'I.

, Thepiston rods I8 preferably fit loosely in the openings I9, flexiblegaskets 29 being mounted upon the under side of the cover plate 20 to permit a limited shifting of the rods within the openings I9 and at the same time retain oil or other liquid within the chamber I2. The gaskets 29 may conveniently beheld in place by plates 30 screwed orotherwise secured to the cover.

The abutment I! is provided with a seat against which the feed screw 8 may seat.

A suitable pump Si is mounted upon the base plate I and provided with supply and delivery connections 32 and 33 respectively. The supply connection 32 is preferably connected to, the

upper portion of the chamber I2, and the delivery connection 33 is connected into the lower portion of the chamber I2, preferably through a passage 34 which may be, formed in the base plate I.

The pump 3| is operated by suitable operating means, as, for example, a hand lever 35, to pump liquid from a supply stored in the upper portion of the chamber I2 above the piston I4 into the lower portion of the'chamber below the piston.

The supply connection 32 is preferably connected into the chamber I2 at a. point ,such that it will be closed bythe piston I4, and the supply of liquid will be thereby interrupted, when the piston reaches its normal limit of movement in the power applying direction. The connection 32 is provided with a suitable check valve 36 to prevent the return flow of liquid, from the pump to the chamber I2.

The delivery connection 33 is preferably provided with a suitable pressure gauge 31, and with a check valve 38 to prevent the return flow of liquid to the pump during the intake stroke thereof.

A return connection 39 is provided to communicate between the lower and upper portions of the chamber I2. The connection 39 may be conveniently connected. with the delivery connection 33 at any convenient point on the chamber side of the check valve 38. The connection 39 opens into the chamber I2 near the top thereof, above the level at which the supply connection 32 opens into the chamber. A hand operated valve II is provided in the connection 39 for opening and closing the connection as desired.

The cylinders 9 and II, pistons I4, pump 3|, and the associated connections therefor, are assembled upon the base plate I, as a compact unit which may be transferred from one press to another as desired. Handles 42 are prefer'- ably provided upon the base plate I to facilitate the handling of the unit.

In use, the unit is applied to a press by removing the feed nut 3 from the feed screw 3 and placing the unit over the feed screw with the base plate I resting upon the pressure plate I of the press. The feed nut 8 is then replaced and advanced along the feed screw 3 until it seats against the top of the abutment It.

The unit may be so applied after the pressure plate has been advanced as far as practicable by the hand operation of the feed nut 8; or it "may be applied at the start of the pressing operation and the feed nut 8 operated to force the pressure plate against the material in the plate by pressure applied through the unit itself..

In either case, after the pressure plate I has been advanced as far as practicable by manual operation of the feed nut, the pump 3| is operated to pump liquid from the upper portion of the chamber I2 into the lower part of thechamber below the piston Id. 7

Since the piston, in the embodiment illustrated in the drawing, is held stationary by the rods I8 seated upon the abutment II, the pumping of liquid into the chamber I2 below the piston causes the base plate I, and cylinders 9 and II carried thereby, to be forced downwardly relative to the piston, thereby forcing the pressure plate I against material within the pressunder the force of pressure developed in the chamber below the piston. When the normal limit of relative movement of the piston I4 within the chamber I2 is reached, the inlet to the supply connections 32 is closed, and the supply of liquid interrupted. a

The valve AI is then opened to permit the return flow of liquid from the lower portion of the chamber to the upper portion, and the piston I 3 is moved downwardly to displace the liquid below the piston into the upper portion of the chamber I2. This may be done by pressing the abutment Il downwardly manually, or by advancing the feed nut 8 thereagainst. The valve 4| is then closed, and the operation repeated until the desired amount of liquid has been pressed from solid material in the press.

The piston rods I8, which are seated in loose engagement with the piston I 4 and the abutment I'I, permit a slight shifting of the rods relative to the piston and abutments, This allows the unit to accomodate itself to inaccuracies of alignment, and permits a slight tilting of the pressure plate I to accomodate inequalities in the depth or unevenness in the surface of the material under the pressure plate I. The rods I8 are symmetrically arranged about the feed screw 3, and serve to prevent binding of the piston within the chamber. The shifting movement of the piston rods also servesto prevent lateral stresses upon the feed screw and cylinders, and to equalize the pressure so that excessive loads will not occur at any one point such as to cause bending or distortion of the feed screw or cylinder. Six of the rods .I8 give satisfactory results, but the number may be increased or decreased if desired.

The provision of. a plurality of piston rods I8 extending through separate openings I9 in the cover plate 20 permits the plate 20 to serve as a rigid reinforcement by which the upper ends of the cylinders 9 and II are tied together and materially braced. This arrangement givesstrength and rigidity to the cylinder structure, and permits the cylinders to be made of much lighter material than would be necessary if the cylinders were not rigidly connected at their upper ends.

I claim:

1. A hydraulic pressure unit for presses comprising a base plate, an abutment, an annular chamber between the base plate and the abutment, an annular piston within the chamber, a plurality of piston rods each having one end pivotally connected to the piston and the other end loosely connected to the abutment, and hydraulic pressure means for effecting relative displacement of the piston and base plate.

2. A hydraulic pressure unit for presses having a feed screw and pressure plate comprising a base plate arranged to be placed over the feed screw above the pressure plate, an annular cylinder upon the base plate and surrounding the feed screw, an annular piston within the cylinder, hydrauliq means for effecting relative displacement of the piston and base plate, an abutment above the cylinder, and a plurality of piston rods pivotally connected at the lower ends thereof to the piston and having their upper ends loosely connected to the abutment and being transversely and tiltably movable relative thereto for equalizing pressure and for preventing lateral stresses upon the feed screw and cylinder.

JOHN ALBERTOLI. 

